The granular activated carbon with high strength was prepared by heating wood phosphate mixture at low temperature and using tar generated during its pyrolysis as binder.
In this paper, the process conditions and plasticizing mechanism of granular activated carbon prepared by phosphoric acid were studied, which provided scientific data and theoretical basis for the preparation of high strength granular activated carbon.
Fir chip as the raw materials, H - POs as activator, using single factor analysis and orthogonal experimental design method, this paper discusses the influence granular activated carbon pore structure and the iodine adsorption value, methylene blue and strength of various preparation factors, determine the optimum process conditions of preparation of granular activated carbon phosphoric acid, phosphoric acid concentration is 70%, dipping 180%, kneading temperature is 170 ℃, for 60 min kneading time, activation temperature is 350 ℃, the activation time of 210 min.The preparation methods of activated carbon include physical method, chemical method, microwave radiation method, etc.(1) Physical method.
Physical method is to use carbon dioxide, water vapor or the mixture of both as activator, the carbonized carbon material and gas in the activation furnace at 500~1200℃ for carbon activation reaction, so that the pore size of the carbonized material to expand, the formation of activated carbon with porous microcrystalline structure.Gas activation method mainly includes carbonization and activation engineering.The so-called carbonization, refers to the low temperature (about 500℃) is small, the volatile coal tar molecules in the material and the thermal decomposition and curing process of asphalt, that is, to remove the volatile in advance, made suitable for the next step of activation with carbonization.
When the temperature is below 600℃, the specific surface area of carbonized material increases with the increase of temperature.When 600~900℃, the specific surface area reaches a certain value: 250~300 m2/g; when above1000℃, the specific surface area shrinks rapidly.yrd coconut carbon
When the carbonization temperature is above 800℃, the reaction performance of carbonized compounds and activation gas gradually becomes weaker, so the carbonization temperature is generally below 1000℃. However, if the residual volatile content and thermal effect are taken into account, the most suitable temperature should be 600~700℃39].chinactivecarbon.com
The carbonized substance obtained from the carbonization process is placed in water vapor or a mixture of water vapor and combustion gas and heat treated at 800~1000℃, which is called the activation process.